Spinetoram is the common name for a mixture of (2R,3aR,5aR,5bS,9S,13S,14R,16aS,16bR)-2-(6-deoxy-3-O-ethyl-2,4-di-O-methyl-α-L-mannopyranosyloxy)-13-[(R2R,5S,6R)-5-(dimethylamino)tetrahydro-6-methylpyran-2-yloxy]-9-ethyl-2,3,3a,4,5,5a,5b,6,9,10,11,12,13,14,16a,16b-hexadecahydro-14-methyl-1H-as-indaceno[3,2-d]oxacyclododecine-7, 15-dione (also known as “dihydro-Et-J”), and (2R,3aR,5aS,5bS,9S,13S,14R,16aS,16bS)-2-(6-deoxy-3-O-ethyl-2,4-di-O-methyl-α-L-mannopyranosyloxy)-13-R2R,5S,6R)-5-(dimethylamino)tetrahydro-6-methylpyran-2-yloxyl-9-ethyl-2,3,3a,5a,5b,6,9,10,11,12,13,14,16a,16b-tetradecahydro-4,14-dimethyl-1H-as-indaceno[3,2-d]oxacyclododecine-7,15-dione (also known as “Et-L”).
Spinetoram can be generated by hydrogenation of the mixture of Et-J and Et-L. U.S. Pat. No. 6,011,981 provides an example synthesis of 5,6-dihydro spinosyn J (example F27) using Wilkinson's catalyst (tris(triphenylphosphine)rhodium(I) chloride (Rh(PPh3)3Cl)) in 7 mole percent (mol %) loading. However, this methodology requires elevated temperature, and the yield needs further improvement. In addition, U.S. Pat. No. 7,683,161 provides certain heterogeneous catalysts for spinetoram synthesis. However, that methodology requires a relative high loading of catalysts. Both U.S. Pat. Nos. 6,011,981 and 7,683,161 are hereby incorporated by reference in their entireties.
Thus, there remains a need for developing new efficient catalysts for spinetoram production with high yields.